Conor James Walsh

Conor James Walsh
Harvard University | Harvard · School of Engineering and Applied Sciences

PhD http://biodesign.seas.harvard.edu

About

231
Publications
95,656
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Introduction
Conor is developing robotic devices that are intended for interacting and cooperating with humans. His current interests include new approaches to design, manufacture and control of wearable robotic devices and characterizing their performance through biomechanical and physiological studies. His group is also working on soft robotic technologies for cardiac applications and applying emerging manufacturing approaches to the design of smart medical tools. http://biodesign.seas.harvard.edu
Additional affiliations
January 2012 - present
Harvard University
Position
  • Research Assistant

Publications

Publications (231)
Article
Full-text available
The force-generating capacity of skeletal muscle is an important metric in the evaluation and diagnosis of musculoskeletal health. Measuring changes in muscle force exertion is essential for tracking the progress of athletes during training, for evaluating patients' recovery after muscle injury, and also for assisting the diagnosis of conditions su...
Article
Full-text available
As we age, humans see natural decreases in muscle force and power which leads to a slower, less efficient gait. Improving mobility for both healthy individuals and those with muscle impairments/weakness has been a goal for exoskeleton designers for decades. In this work, we discover that significant reductions in the energy cost required for walkin...
Article
Full-text available
Background Stroke is a leading cause of serious gait impairments and restoring walking ability is a major goal of physical therapy interventions. Soft robotic exosuits are portable, lightweight, and unobtrusive assistive devices designed to improve the mobility of post-stroke individuals through facilitation of more natural paretic limb function du...
Article
Traditional orthopedic casting strategies used in the treatment of fractured limbs, such as fiberglass and plaster‐based tapes, suffer from several drawbacks, including technically challenging molding for application, occurrence of skin complications, and the requirement of a potentially hazardous oscillatory saw for removal, which is frightening f...
Chapter
Stroke is a leading medical issue that can impact the person’s ability to walk effectively. There is limited research into the design and biomechanical response for exosuits that assist more proximal joints such as the hip. For this case series, three subjects with chronic stroke participated in a single-session study to evaluate hip flexion exosui...
Chapter
Ankle exosuits/exoskeletons can improve gait but the assistance needs to be tuned to the individual. We suspect that ankle assistance can affect underlying muscle-tendon dynamics and should be accounted for in the control design. We highlight two complementary studies that begin to address these issues. First, we use ultrasound imaging to directly...
Article
Full-text available
Background: Ankle-targeting resistance training for improving plantarflexion function during walking increases rehabilitation intensity, an important factor for motor recovery after stroke. However, understanding of the effects of resisting plantarflexion during stance on joint kinetics and muscle activity-key outcomes in evaluating its potential...
Article
Full-text available
Population aging is a defining demographic reality of our era. It is associated with an increase in the societal burden of delivering care to older adults with chronic conditions or frailty. How to integrate global population aging and technology development to help address the growing demands for care facing many aging societies is both a challeng...
Article
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We present the use of a single inertial measurement unit (IMU) worn on the thigh to produce stride-by-stride estimates of walking speed and its spatiotemporal determinants (i.e., stride time and stride length). Ten healthy and eight post-stroke individuals completed a 6-min walk test with an 18-camera motion capture system used for ground truth mea...
Article
Full-text available
Mechanical stimulation (mechanotherapy) can promote skeletal muscle repair, but a lack of reproducible protocols and mechanistic understanding of the relation between mechanical cues and tissue regeneration limit progress in this field. To address these gaps, we developed a robotic device equipped with real-time force control and compatible with ul...
Article
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Purpose In clinical practice, many patients with right heart failure (RHF) have elevated pulmonary artery pressures and increased afterload on the right ventricle (RV). In this study, we evaluated the feasibility of RV augmentation using a soft robotic right ventricular assist device (SRVAD), in cases of increased RV afterload. Methods In nine Yor...
Article
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Background: Soft robotic exosuits can facilitate immediate increases in short- and long-distance walking speeds in people with post-stroke hemiparesis. We sought to assess the feasibility and rehabilitative potential of applying propulsion-augmenting exosuits as part of an individualized and progressive training program to retrain faster walking an...
Article
The addition of a load during walking requires changes in the movement pattern. The investigation of the dynamic joint stiffness behavior may help to understand the lower limb joints’ contribution to these changes. This study aimed to investigate the dynamic stiffness of lower limb joints in response to the increased load carried while walking. Thi...
Article
Millimeter-sized electrostatic film actuators, inspired by the efficient spatial arrangement of insect muscles, achieve a muscle-like power density (61 W kg ⁻¹ ) and enable robotic applications in which agility is needed in confined spaces. Like biological muscles, these actuators incorporate a hierarchical structure, in this case building from ele...
Article
Full-text available
Textiles have emerged as a promising class of materials for developing wearable robots that move and feel like everyday clothing. Textiles represent a favorable material platform for wearable robots due to their flexibility, low weight, breathability, and soft hand‐feel. Textiles also offer a unique level of programmability because of their inheren...
Article
Full-text available
In article number 2008278, Vanessa Sanchez, Conor J. Walsh, and Robert J. Wood review the state of the art in textile‐based wearable robots. The application areas for textile robots and their diverse needs drive materials innovations for textile actuators, sensors, and integration elements. Advances in materials and production technologies suggest...
Article
Textile based pneumatic actuators have recently seen increased development for use in wearable applications thanks to their high strength to weight ratio and range of achievable actuation modalities. However, the design of these textile-based actuators is typically an iterative process due to the complexity of predicting the soft and compliant beha...
Article
Full-text available
Hemiparetic walking after stroke is typically slow, asymmetric, and inefficient, significantly impacting activities of daily living. Extensive research shows that functional, intensive, and task-specific gait training is instrumental for effective gait rehabilitation, characteristics that our group aims to encourage with soft robotic exosuits. Howe...
Article
Full-text available
Soft machines are a promising design paradigm for human-centric devices1,2 and systems required to interact gently with their environment3,4. To enable soft machines to respond intelligently to their surroundings, compliant sensory feedback mechanisms are needed. Specifically, soft alternatives to strain gauges—with high resolution at low strain (l...
Article
Date Presented 03/26/20 Thirteen participants with cervical SCI used a soft robotic glove in a variety of tests compared to their baseline function. Results included a 50% improvement on the Jebsen-Taylor Hand Function Test from baseline to glove trial and significant increases in grasp and pinch forces with the active glove. The glove was controll...
Article
In article number 2000383, Conor J. Walsh and co‐workers present a thermally actuated robotic textile driven by liquid‐vapor phase change. A laminated batch fabrication process enables manufacturing of customizable individual and arrayed soft robotic textile modules incorporating a resistive textile heater and a capacitive textile pressure sensor....
Article
Soft robots have attracted attention for biomedical and consumer devices. However, most of these robots are pneumatically actuated, requiring a tether and thus limiting wearable applications that require multiple controlled actuators. By pairing liquid‐vapor phase change actuation with a textile‐based laminated manufacturing method, smart thermally...
Article
Full-text available
Background: The anterior-posterior ground reaction force (AP-GRF) and propulsion and braking point metrics derived from the AP-GRF time series are indicators of locomotor function across healthy and neurological diagnostic groups. In this paper, we describe the use of a minimal set of wearable inertial measurement units (IMUs) to indirectly measur...
Article
Soft robotic devices have been proposed as an alternative solution for ventricular assistance. Unlike conventional ventricular assist devices (VADs) that pump blood through an artificial lumen, soft robotic VADs (SRVADs) use pneumatic artificial muscles (PAM) to assist native contraction and relaxation of the ventricle. Synchronization of SRVADs is...
Article
Full-text available
In individuals with motor impairments such as those post-stroke or with cerebral palsy, the function of the knee extensors may be affected during walking, resulting in decreased mobility. We have designed a lightweight, hinge-free wearable robot combining soft textile exosuit components with integrated rigid components, which assists knee extension...
Article
People with tetraplegia resulting from spinal cord injury experience debilitating hand impairments that may lead to lifelong dependence on others to perform activities of daily living. Wearable robotic devices that actively support hand function during daily living tasks could bring great benefits to this population. In this work, the performance o...
Article
Full-text available
Objective: Soft robotic exosuits can improve the mechanics and energetics of walking after stroke. Building on this prior work, we evaluated the effects of the first prototype of a portable soft robotic exosuit. Methods: Exosuit-induced changes in the overground walking speed, distance, and energy expenditure of individuals post-stroke were eval...
Article
Full-text available
Intense therapy is a key factor to improve rehabilitation outcomes. However, when performing rehabilitative stretching with the upper limb of stroke survivors, therapist fatigue is often the limiting factor for the number of repetitions per session. In this paper we present an inflatable soft wearable robot aimed at improving severe stroke rehabili...
Preprint
Full-text available
Background: The anterior-posterior ground reaction force (AP-GRF) and propulsion and braking metrics derived from the AP-GRF time series are meaningful indicators of locomotor function across healthy and neurological diagnostic groups. In this paper, we describe the use of a minimal set of wearable inertial measurement units (IMUs) to indirectly me...
Preprint
Full-text available
Background: The anterior-posterior ground reaction force (AP-GRF) and propulsion and braking metrics derived from the AP-GRF time series are indicators of locomotor function across healthy and neurological diagnostic groups. In this paper, we describe the use of a minimal set of wearable inertial measurement units (IMUs) to indirectly measure the A...
Article
Full-text available
Left ventricular failure is strongly associated with secondary mitral valve regurgitation. Implantable soft robotic devices are an emerging technology that enables augmentation of a native function of a target tissue. We demonstrate the ability of a novel soft robotic ventricular assist device to dynamically augment left ventricular contraction, pr...
Article
Lowering locomotion's metabolic cost Walking and running require different gaits, with each type of motion putting a greater bias on different muscles and joints. Kim et al. developed a soft, fully portable, lightweight exosuit that is able to reduce the metabolic rate for both running and walking by assisting each motion via the hip extension (see...
Article
Full-text available
Different adaptation rates have been reported in studies involving ankle exoskeletons designed to reduce the metabolic cost of their wearers. This work aimed to investigate energetic adaptations occurring over multiple training sessions, while walking with a soft exosuit assisting the hip joint. The participants attended five training sessions with...
Article
Periodic actuation of multiple soft, pneumatic actuators requires coordinated function of multiple, separate components. This work demonstrates a soft, pneumatic ring oscillator that induces temporally coordinated periodic motion in soft actuators using a single, constant-pressure source, without hard valves or electronic controls. The fundamental...
Article
Robotic artificial muscles are a subset of artificial muscles that are capable of producing biologically inspired motions useful for robot systems, i.e., large power-to-weight ratios, inherent compliance, and large range of motions. These actuators, ranging from shape memory alloys to dielectric elastomers, are increasingly popular for biomimetic r...
Patent
Full-text available
Embodiments of the invention provide a laparoscopic morcellating device and method for removing tissue from a body cavity. The morcellating device includes a containment mechanism having an aperture, a cutting mechanism designed to fit into an interior space of the containment mechanism and a retractor mechanism that is coupled to the cutting mecha...
Article
Hemiparetic gait is abnormal asymmetric walking, often observed among patients with cerebral palsy or stroke. One of the major features of asymmetric gait is excessive reliance on the healthy leg, which results in improper load shift, slow walking speed, higher metabolic cost, and weakness of the unused leg. Hence, clinically it is desirable to pro...
Article
Textiles are promising materials to realize the next generation of pneumatic soft robots as they are lightweight, conformable, stretchable, and intrinsically anisotropic. Exploiting these properties, here we describe the fabrication and mechanical characterization of a new type of bending textile actuator. The actuator is fabricated using a laminat...
Chapter
Exosuits and exoskeletons have been shown to reduce the metabolic cost of walking by over 20%. While many studies have shown promising group-averaged data, there has often been high variability in individual response to assistance even when using standardized procedures and device platforms. Here, we aim to investigate the biomechanical differences...
Article
Full-text available
Previous ankle exoskeleton assistance techniques that were able to demonstrate metabolic reductions can be categorized into those that delivered moment profiles similar to the biological ankle moment throughout the stance phase, and others that delivered positive power only during push off. Both assistance techniques and a powered-off condition wer...
Conference Paper
Full-text available
Nascent endoscopic therapeutic procedures, such as endoscopic submucosal dissection, enable unparalleled access to and removal of mid-size cancerous neoplasia from within the gastrointestinal tract. However, the remote locations of these lesions often incur substantial distal dexterity which imparts appreciable cognitive loading on the clinician an...
Article
Full-text available
Recent technologic advancements have enabled the creation of portable, low-cost, and unobtrusive sensors with tremendous potential to alter the clinical practice of rehabilitation. The application of wearable sensors to track movement has emerged as a promising paradigm to enhance the care provided to patients with neurologic or musculoskeletal con...
Article
This study examines how adults apply forces to regulate new walkers’ body sway directions while assisting them in standing and initiating their first steps. Eight healthy, typically developing young children who could stand independently and walk a few steps with an adult’s support participated in this study and were included for data analyses. Adu...
Article
Full-text available
Knit, woven, and nonwoven fabrics offer a diverse range of stretch and strain limiting mechanical properties that can be leveraged to produce tailored, whole-body deformation mechanics of soft robotic systems. This work presents new insights and methods for combining heterogeneous fabric material layers to create soft fabric-based actuators. This w...
Article
Full-text available
Background Soft exosuits are a recent approach for assisting human locomotion, which apply assistive torques to the wearer through functional apparel. Over the past few years, there has been growing recognition of the importance of control individualization for such gait assistive devices to maximize benefit to the wearer. In this paper, we present...
Article
Full-text available
Background Spinal cord injury is a devastating condition that can dramatically impact hand motor function. Passive and active assistive devices are becoming more commonly used to enhance lost hand strength and dexterity. Soft robotics is an emerging discipline that combines the classical principles of robotics with soft materials and could provide...